Digital Breast Tomosynthesis: A Further Evolution of Digital Mammography

The field of radiology is constantly evolving and the Breast Imaging Group at UCSF is proud to stay on the forefront with the latest technologies. Most recently, the UCSF Department of Radiology and Biomedical Imaging has unveiled digital breast tomosynthesis, the latest evolution of digital mammography, for our patients. The new technique for breast cancer screening is ready for clinical use now at San Francisco General Hospital.

What is DBT?

Digital breast tomosynthesis (DBT) is a further evolution of digital mammography, in which a series of low dose projection images of the breast are obtained at different angles.  The data obtained from the projections is reconstructed using a computer algorithm into a series of images that are focused on different planes through the breast.  This approach greatly reduces the problem of overlapping tissue, which can hide cancers.  It also reduces false positive callbacks due to superimposed normal tissue structures that can simulate an abnormal breast lesion. 

In numerous clinical studies, DBT has been shown to reduce the false positive screening callback rate while simultaneously increasing the cancer detection rate.  Research is ongoing to determine whether DBT may have greater benefit for certain groups of women, particularly those with dense breast tissue.  Currently, we are offering DBT as an option to all women undergoing screening mammography.  We will also use DBT selectively for diagnostic mammography at the discretion of the radiologist or request of referring clinician.

History of DBT

Tomographic imaging techniques to obtain planes focused at different levels through a tissue structure have been available for many decades, but it remained a cumbersome technique associated with high radiation dose.  It was not until the 1990s when the combination of digital X-ray detectors and fast computing techniques enabled the development of the first prototype DBT system.  This work was pioneered by a research team at Massachusetts General Hospital.  The modern DBT system is capable of acquiring of high resolution images with 1 mm spacing through the breast at the same speed and low radiation dose as for conventional digital mammography.    

DBT vs. conventional mammography

While conventional mammography is certainly a lifesaving tool, DBT represents a significant step forward.  DBT has the potential to detect some cancers at screening that are not visible by conventional mammography, the majority of which are invasive cancers.  Additionally, DBT has been shown to reduce false positive callbacks at screening. For patients referred for a breast symptom or workup of an imaging finding, DBT may enable more definitive and efficient characterization of breast abnormalities.  


As is the UCSF standard, we take the utmost care to minimize radiation dose and ensure patient safety while maintaining the highest quality diagnostic imaging. It is the combination of our world-renowned physicians, leading edge technology, and our highly skilled and caring team members that have resulted in our reputation as the trusted resource for mammography in the Bay Area.  On a national level, UCSF is designated a Breast Imaging Center of Excellence by the American College of Radiology.  Compared to other breast imaging centers in the US, UCSF has consistently demonstrated higher than average cancer detection rates as well as lower than average screening recall rates.*

Through research and innovation, the field of radiology is constantly advancing with new technologies. To learn more about new research and innovation from the Breast Imaging Group at UCSF, including the state-of-the-art digital breast tomosynthesis, please click here.

*Source: American College of Radiology National Mammography Database and Breast Cancer Surveillance Consortium

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